Keithley 6514 User Manual

Model 6514 System Electrometer

Instruction Manual

A GREATER MEASURE OF CONFIDENCE

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a
period of 1 year from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables,
rechargeable batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defecti ve.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in

Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation
prepaid, to the indicated service facility . Repairs will be made and the product returned, transportation prepaid.
Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.

LIMIT A TION OF W ARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written
consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-rechar geable
batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUD­ING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE.
THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR
ANY DIRECT , INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS
BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAM­AGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION,
LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR D AMAGE TO PROPERTY.

A G R E A T E R M E A S U R E O F C O N F I D E N C E

Corporate Headquarters

Belgium:

Sint-Pieters-Leeuw • 02-363 00 40 • Fax: [phone] • www.keithley.nl

China:

Beijing • 8610-82251886 • Fax: [phone] • www .k eithley.com.cn

Finland:

Helsinki • 09-5306-6560 • Fax: [phone] • www .k eithley.com

France:

Saint-Aubin • 01-64 53 20 20 • F ax: 01-60 11 77 26 • www .keithle y.fr

Germany:

Germering • 089/84 93 07-40 • Fax: [phone] • www.keithley.de

Great Britain:
India:

Theale • 0118 929 7500 • Fax: [phone] • www .keithle y.co.uk

Bangalore • 91-80 2212 8027 • Fax: [phone] • www .k eithley.com

• 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • F ax: 440-248-6168 • 1-888-KEITHLEY (534-8453) • www .keithle y .com

Keithley Instruments, Inc.

Italy:

Milano • 02-48 39 16 01 • Fax: [phone] • www .k eithley.it

Japan:

Tokyo • 81-3-5733-7555 • Fax: [phone] • www .k eithley.jp

Korea:

Seoul • 82-2-574-7778 • Fax: [phone] • www .k eithley.com

Netherlands:
Singapore:
Sweden:
Taiwan:

Singapore • 65-6747-9077 • Fax: [phone] • www .k eithley.com

Solna • 08-509 04 600 • Fax: [phone] • www .k eithley.com

Hsinchu • 886-3-572-9077 • Fax: [phone] • www .k eithley.com.tw

Gorinchem • 0183-635333 • Fax: [phone] • www .k eithley.nl

3/04

Model 6514 System Electrometer

Instruction Manual

©1998, Keithley Instruments, Inc.

All rights reserved.

Cleveland, Ohio, U.S.A.

Fourth Printing, May 2003

Document Number: 6514-901-01 Rev. D

Manual Print History

The print history shown below lists the printing dates of all Revisions and Addenda created
for this manual. The Revision Level letter increases alphabetically as the manual undergoes
subsequent updates. Addenda, which are released between Re visions, contain important change
information that the user should incorporate immediately into the manual. Addenda are
numbered sequentially. When a new Revision is created, all Addenda associated with the
previous Revision of the manual are incorporated into the new Revision of the manual. Each
new Revision includes a revised copy of this print history page.

Revision A (Document Number 6514-901-01)............................................................October 1998

Addendum A (Document Number 6514-901-02).....................................................December 1998

Revision B (Document Number 6514-901-01)........................................................ December 1998

Revision C (Document Number 6514-901-01)................................................................. June 1999

Revision D (Document Number 6514-901-01).................................................................May 2003

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

S

afety Precautions

The following safety precautions should be observed before using this product and any associated instrumentation. Although
some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous
conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions
required to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before us­ing the product. Refer to the manual for complete product specifications.

If the product is used in a manner not specified, the protection provided by the product may be impaired.
The types of product users are:

Responsible body

ment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.

Operators

instrument. They must be protected from electric shock and contact with hazardous live circuits.

Maintenance personnel

voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state
if the operator may perform them. Otherwise, they should be performed only by service personnel.

Service personnel

trained service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that are rated Measurement Category I and Measurement Category

II, as described in the International Electrotechnical Commission (IEC) Standard IEC 60664. Most measurement, control, and
data I/O signals are Measurement Category I and must not be directly connected to mains voltage or to voltage sources with
high transient over-voltages. Measurement Category II connections require protection for high transient over-voltages often
associated with local AC mains connections. Assume all measurement, control, and data I/O connections are for connection to
Category I sources unless otherwise marked or described in the Manual.

Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test fixtures.
The American National Standards Institute (ANSI) states that a shock hazard exists when v oltage le vels greater than 30V RMS,

42.4V peak, or 60VDC are present.

circuit before measuring.

Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators
are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect themselves from the risk of electric shock.
If the circuit is capable of operating at or above 1000 volts,

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance limited
sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protectiv e
devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the
connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input
power disconnect device must be provided, in close proximity to the equipment and within easy reach of the operator.

For maximum safety , do not touch the product, test cables, or any other instruments while power is applied to the circuit under
test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting

is the individual or group responsible for the use and maintenance of equipment, for ensuring that the equip-

use the product for its intended function. They must be trained in electrical safety procedures and proper use of the

perform routine procedures on the product to keep it operating properly, for example, setting the line

are trained to work on live circuits, and perform safe installations and repairs of products. Only properly

A good safety practice is to expect that hazardous voltage is present in any unknown

no conductive part of the circuit may be exposed.

5/03

cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground.

Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being
measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the
equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating
information, and as shown on the instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use

of a lid interlock.
If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.

!

The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of
normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.

The symbol indicates a connection terminal to the equipment frame.
The

WARNING

information very carefully before performing the indicated procedure.
The

CAUTION

warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer,

test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety
approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from
other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only
through Keithley Instruments to maintain accuracy and functionality of the product.) If you are unsure about the applicability
of a replacement component, call a Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with
no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled accord­ing to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for
proper cleaning/servicing.

heading in a manual explains dangers that might result in personal injury or death. Al ways read the associated

heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the

Table of Contents

1 Getting Started

General information ................................................................... 1-2

Warranty information .......................................................... 1-2

Contact information ............................................................ 1-2

Safety symbols and terms ................................................... 1-2

Inspection ............................................................................ 1-2

Options and accessories ...................................................... 1-3

System electrometer features ..................................................... 1-4

Front and rear panel familiarization ........................................... 1-5

Front panel summary .......................................................... 1-5

Rear panel summary ........................................................... 1-8

Power-up .................................................................................. 1-10

Line power connection ...................................................... 1-10

Line frequency selection ................................................... 1-10

Power-up sequence ........................................................... 1-11

Display ..................................................................................... 1-12

Status and error messages ................................................. 1-12

Default settings ......................................................................... 1-12

SCPI programming .................................................................. 1-15

2 Measurement Concepts

Measurement overview .............................................................. 2-2

Performance considerations ....................................................... 2-2

Warm-up period .................................................................. 2-2

Autozero .............................................................................. 2-2

Connection fundamentals ........................................................... 2-3

Input connector ................................................................... 2-3

Low noise input cables ........................................................ 2-5

Basic connections to DUT .................................................. 2-6

Test fixture .......................................................................... 2-9

Input protection ................................................................. 2-11

Floating measurements ..................................................... 2-11

Zero check and zero correct ..................................................... 2-13

Zero check ......................................................................... 2-13

Zero correct ....................................................................... 2-14

SCPI programming — zero check and zero correct ......... 2-15

Input bias current and offset voltage calibration ...................... 2-17

Front panel ........................................................................ 2-17

SCPI programming ........................................................... 2-18

Measurement considerations .................................................... 2-19

3Volts and Ohms Measurements

Measurement overview ............................................................... 3-2

Guarding ..................................................................................... 3-2

Test circuit leakage .............................................................. 3-2

Input cable leakage and capacitance ................................... 3-3

Volts and ohms measurement procedure .................................... 3-4

V-Drop and I-Source for ohms ............................................ 3-6

SCPI programming ..................................................................... 3-7

Programming example ........................................................ 3-8

Volts and ohms measurement considerations ............................. 3-9

Loading effects .................................................................... 3-9

Cable leakage resistance ...................................................... 3-9

Input capacitance (settling time) ....................................... 3-10

Guarding input cable ......................................................... 3-12

Application ............................................................................... 3-14

Capacitor dielectric absorption .......................................... 3-14

4 Amps Measurements

Measurement overview ............................................................... 4-2

Amps measurement procedure ................................................... 4-2

Damping .............................................................................. 4-4

High impedance measurement techniques ................................. 4-5

SCPI programming ..................................................................... 4-8

Programming example ........................................................ 4-9

Amps measurement considerations ............................................ 4-9

Input bias current ................................................................. 4-9

Voltage burden ..................................................................... 4-9

Noise .................................................................................. 4-10

Applications .............................................................................. 4-13

Diode leakage current ........................................................ 4-13

Capacitor leakage current .................................................. 4-14

Cable insulation resistance ................................................ 4-14

Surface insulation resistance (SIR) ................................... 4-15

5 Coulombs Measurements

Measurement overview ............................................................... 5-2

Auto discharge ............................................................................ 5-2

Coulombs measurement procedure ............................................ 5-3

SCPI programming ..................................................................... 5-5

Programming example ........................................................ 5-6

Coulombs measurement considerations ..................................... 5-6

Input bias current ................................................................. 5-6

External voltage source ....................................................... 5-6

Zero check hop and auto discharge hop .............................. 5-7

Application ................................................................................. 5-7

Capacitance measurements ................................................. 5-7

6 Range, Units, Digits, Rate, and Filters

Range, units, and digits .............................................................. 6-2

Range .................................................................................. 6-2

Units .................................................................................... 6-4

Digits ................................................................................... 6-4

SCPI programming - range and digits ................................ 6-4

Rate ............................................................................................ 6-6

SCPI programming — rate ................................................. 6-7

Filters ......................................................................................... 6-8

Median filter ........................................................................ 6-8

Digital filter ......................................................................... 6-9

SCPI programming — filters ............................................ 6-10

7 Relative, mX+b and Percent (%)

Relative ....................................................................................... 7-2

Setting and controlling relative ........................................... 7-2

SCPI programming — relative ........................................... 7-3

mX+b and percent (%) ............................................................... 7-4

mX+b .................................................................................. 7-4

Percent (%) .......................................................................... 7-5

SCPI programming — mX+b and percent ......................... 7-6

8 Buffer

Buffer operations ........................................................................ 8-2

Store .................................................................................... 8-2

Recall .................................................................................. 8-2

Buffer statistics ................................................................... 8-3

SCPI programming .................................................................... 8-4

Programming example......................................................... 8-6

9Triggering

Trigger models ........................................................................... 9-2

Idle and initiate ................................................................... 9-4

Trigger model operation ...................................................... 9-4

Trigger model configuration — front panel ........................ 9-7

SCPI programming ..................................................................... 9-9

Programming example ...................................................... 9-10

External triggering ................................................................... 9-11

Input trigger requirements ................................................. 9-11

Output trigger specifications ............................................. 9-12

External trigger example ................................................... 9-12

10 Limit T ests

Limit testing .............................................................................. 10-2

Binning ..................................................................................... 10-4

Component handler interface ............................................ 10-6

Component handler types .................................................. 10-7

Digital output clear pattern ................................................ 10-8

Front panel operation .............................................................. 10-10

Limit test configuration ................................................... 10-10

Perform limit tests ........................................................... 10-11

SCPI programming ................................................................. 10-12

Programming example .................................................... 10-15

11 Digital I/O, Analog Outputs, and External Feedback

Digital I/O port ......................................................................... 11-2

Sink mode — controlling external devices ....................... 11-3

Source mode — logic control ............................................ 11-5

Setting digital output lines ................................................. 11-5

SCPI programming — digital output pattern .................... 11-6

Analog outputs .......................................................................... 11-7

2V analog output ............................................................... 11-7

External feedback ................................................................... 11-11

Electrometer input circuitry ............................................ 11-11

Shielded fixture construction ........................................... 11-12

Non-standard coulombs ranges ....................................... 11-13

External feedback procedure ........................................... 11-13

Logarithmic currents ....................................................... 11-15

Non-decade current gains ................................................ 11-16

SCPI programming — external feedback ....................... 11-17

12 Remote Operation

Selecting and configuring an interface ..................................... 12-2

Interfaces ........................................................................... 12-2

Languages .......................................................................... 12-2

Interface selection and configuration procedures .............. 12-2

GPIB operation and reference .................................................. 12-5

GPIB bus standards ........................................................... 12-5

GPIB bus connections ....................................................... 12-5

Primary address selection .................................................. 12-7

General bus commands ..................................................... 12-8

Front panel GPIB operation ............................................ 12-10

Programming syntax ....................................................... 12-11

RS-232 interface reference ..................................................... 12-17

Sending and receiving data .............................................. 12-17

RS-232 settings ............................................................... 12-17

RS-232 connections ......................................................... 12-18

Error messages ................................................................ 12-19

13 Status Structure

Overview .................................................................................. 13-2

Clearing registers and queues ................................................... 13-4

Programming and reading registers ......................................... 13-5

Programming enable registers ........................................... 13-5

Reading registers ............................................................... 13-6

Status byte and service request (SRQ) ..................................... 13-7

Status byte register ............................................................ 13-7

Service request enable register .......................................... 13-8

Serial polling and SRQ ..................................................... 13-9

Status byte and service request commands ....................... 13-9

Status register sets .................................................................. 13-11

Register bit descriptions .................................................. 13-11

Condition registers .......................................................... 13-15

Event registers ................................................................. 13-16

Event enable registers ..................................................... 13-17

Queues .................................................................................... 13-18

Output queue ................................................................... 13-18

Error queue ...................................................................... 13-19

14 Common Commands
15 SCPI Signal Oriented Measurement Commands
16 DISPlay , FORMat, and SYSTem

DISPlay subsystem .................................................................. 16-2

FORMat subsystem .................................................................. 16-4

SYSTem subsystem .................................................................. 16-8

17 SCPI Reference T ables

General notes ............................................................................ 17-2

18 Performance V erification

Introduction .............................................................................. 18-2

Verification test requirements ................................................... 18-3

Environmental conditions ................................................. 18-3

Warm-up period ................................................................ 18-3

Line power ........................................................................ 18-3

Recommended test equipment ................................................. 18-4

Verification limits ..................................................................... 18-6

Example reading limits calculation ................................... 18-6

Recalculating resistance reading limits ............................. 18-6

Calibrator voltage calculations ................................................. 18-7

Current calculations .......................................................... 18-7

Charge calculations ........................................................... 18-7

Performing the verification test procedures .............................. 18-8

Test summary .................................................................... 18-8

Test considerations ............................................................ 18-8

Restoring factory defaults ......................................................... 18-9

Input bias current and offset voltage calibration ...................... 18-9

Offset voltage calibration .................................................. 18-9

Input bias current calibration ............................................. 18-9

Volts measurement accuracy .................................................. 18-10

Amps measurement accuracy ................................................. 18-12

20µA-20mA range accuracy ........................................... 18-12

20pA-2µA range accuracy .............................................. 18-13

Ohms measurement accuracy ................................................. 18-15

2k

Ω

-20MΩ range accuracy ............................................. 18-15

200M

Ω

-200GΩ range accuracy ...................................... 18-17

Coulombs measurement accuracy .......................................... 18-18

19 Calibration

Introduction .............................................................................. 19-2

Environmental conditions ......................................................... 19-2

Temperature and relative humidity..................................... 19-2

Warm-up period ................................................................. 19-2

Line power ......................................................................... 19-2

Calibration considerations ........................................................ 19-3

Calibration cycle ................................................................ 19-3

Recommended calibration equipment ...................................... 19-3

Calibration errors ...................................................................... 19-5

Calibration menu ...................................................................... 19-5

Aborting calibration .................................................................. 19-5

Current and charge calculations ............................................... 19-6

Manual calculations............................................................ 19-6

Automatic calculations ...................................................... 19-6

Calibration procedure ............................................................... 19-7

Preparing for calibration .................................................... 19-7

Input bias current and offset voltage calibration ............... 19-7

Volts calibration ................................................................. 19-8

Amps calibration ............................................................. 19-10

Coulombs calibration ...................................................... 19-14

Ohms calibration ............................................................. 19-16

Entering calibration dates and saving calibration ............ 19-18

Locking out calibration ................................................... 19-18

Changing the calibration code ................................................ 19-18

Resetting the calibration code ................................................ 19-19

Displaying calibration dates ................................................... 19-19

Displaying the calibration count ............................................. 19-20

20 Routine Maintenance

Introduction .............................................................................. 20-2

Setting line voltage and replacing line fuse ............................. 20-2

Front panel tests ................................................................ 20-4

DISP test ........................................................................... 20-4

KEY test ............................................................................ 20-4

A Specifications
B Status and Error Messages
C General Measurement Considerations

Measurement considerations ..................................................... C-2

Ground loops ...................................................................... C-2

Triboelectric effects ........................................................... C-3

Piezoelectric and stored charge effects .............................. C-3

Electrochemical effects ...................................................... C-4

Humidity ............................................................................ C-4

Light ................................................................................... C-4

Electrostatic interference ................................................... C-4

Magnetic fields ................................................................... C-5

Electromagnetic Interference (EMI) .................................. C-5

D DDC Emulation Commands

DDC language ........................................................................... D-2

E Example Programs

Programming examples .............................................................. E-2

Changing function and range .............................................. E-2

One-shot triggering ............................................................. E-3

Generating SRQ on buffer full ............................................ E-4

Storing readings in buffer ................................................... E-5

Taking readings using the :READ? command .................... E-6

Controlling the Model 6514 via the RS-232 COM2 port ... E-7

F IEEE-488 Bus Overview

Introduction ............................................................................... F-2

Bus description .......................................................................... F-3

Bus lines .................................................................................... F-5

Data lines ............................................................................ F-5

Bus management lines ........................................................ F-5

Handshake lines .................................................................. F-6

Bus commands ........................................................................... F-7

Uniline commands .............................................................. F-8

Universal multiline commands ........................................... F-8

Addressed multiline commands ......................................... F-9

Address commands ............................................................ F-9

Unaddress commands ......................................................... F-9

Common commands ......................................................... F-10

SCPI commands ............................................................... F-10

Command codes ............................................................... F-10

Typical command sequences ............................................ F-11

IEEE command groups ..................................................... F-12

Interface function codes .......................................................... F-13

G IEEE-488 and SCPI Conformance Information

Introduction ............................................................................... G-2

H Calibration Options

Introduction ............................................................................... H-2

Reading calibration standard values .......................................... H-2

Data transfer connections ................................................... H-2

Reading values ................................................................... H-2

Example program ............................................................... H-3

Remote calibration ..................................................................... H-4

Calibration commands ........................................................ H-4

Remote calibration overview .............................................. H-4

List of Illustrations

1 Getting Started

Figure 1-1 Model 6514 front panel .......................................................... 1-5

Figure 1-2 Model 6514 rear panel ........................................................... 1-8

2 Measurement Concepts

Figure 2-1 Input connector configurations .............................................. 2-4

Figure 2-2 Maximum input levels ........................................................... 2-5

Figure 2-3 Basic connections for unguarded measurements ................... 2-6

Figure 2-4 Shielding for unguarded measurements ................................. 2-7

Figure 2-5 Basic connections for guarded measurements ....................... 2-8

Figure 2-6 General purpose test fixture ................................................... 2-9

Figure 2-7 Capacitor test circuit without protection .............................. 2-11

Figure 2-8 Capacitor test circuit with protection ................................... 2-11

Figure 2-9 Floating measurements ........................................................ 2-12

Figure 2-10 Equivalent input impedance with zero check enabled ......... 2-14

3Volts and Ohms Measurements

Figure 3-1 High-impedance voltage measurements ................................ 3-3

Figure 3-2 Connections for unguarded volts and ohms ........................... 3-5

Figure 3-3 Connections for guarded volts and ohms ............................... 3-6

Figure 3-4 Meter loading ......................................................................... 3-9

Figure 3-5 Effects of input capacitance ................................................. 3-11

Figure 3-6 Settling time ......................................................................... 3-12

Figure 3-7 Unguarded input cable ......................................................... 3-12

Figure 3-8 Guarded input cable ............................................................. 3-13

Figure 3-9 Measuring dielectric absorption ........................................... 3-15

4 Amps Measurements

Figure 4-1 Connections for amps ............................................................ 4-4

Figure 4-2 High impedance current measurements ................................. 4-5

Figure 4-3 Floating current measurements .............................................. 4-7

Figure 4-4 Voltage burden considerations ............................................. 4-10

Figure 4-5 Source resistance and capacitance ....................................... 4-11

Figure 4-6 Connections; diode leakage current test .............................. 4-13

Figure 4-7 Connections; capacitor leakage current test ......................... 4-14

Figure 4-8 Connections; cable insulation resistance test ....................... 4-14

Figure 4-9 Connections; surface insulation resistance test .................... 4-15

5 Coulombs Measurements

Figure 5-1 Typical connections for coulombs .......................................... 5-4

Figure 5-2 Measuring capacitors ............................................................. 5-7

6 Range, Units, Digits, Rate, and Filters

Figure 6-1 Speed vs. noise characteristics ............................................... 6-6

Figure 6-2 Digital filter types; moving and repeating .............................. 6-9

8 Buffer

Figure 8-1 Buffer locations ...................................................................... 8-3

9Triggering

Figure 9-1 Trigger model — front panel operation ................................. 9-2

Figure 9-2 Trigger model — remote operation ........................................ 9-3

Figure 9-3 Measure action block of trigger model .................................. 9-6

Figure 9-4 Trigger link connection operation ........................................ 9-11

Figure 9-5 Trigger link input pulse specifications ................................. 9-11

Figure 9-6 Trigger link output pulse specifications ............................... 9-12

Figure 9-7 DUT test system ................................................................... 9-12

Figure 9-8 Trigger link connections ....................................................... 9-13

Figure 9-9 Operation model for triggering example .............................. 9-14

10 Limit T ests

Figure 10-1 Limit tests ............................................................................. 10-2

Figure 10-2 Limit tests example .............................................................. 10-2

Figure 10-3 Operation model for limit test .............................................. 10-3

Figure 10-4 Binning system ..................................................................... 10-4

Figure 10-5 Operation model for limit testing with binning .................... 10-5

Figure 10-6 Handler interface connections .............................................. 10-6

Figure 10-7 Digital output auto-clear timing example ............................. 10-9

11 Digital I/O, Analog Outputs, and External Feedback

Figure 11-1 Digital I/O port ..................................................................... 11-2

Figure 11-2 Digital I/O port simplified schematic ................................... 11-3

Figure 11-3 Controlling externally powered relays ................................. 11-4

Figure 11-4 NAND gate control .............................................................. 11-5

Figure 11-5 Typical 2V analog output connections ................................. 11-8

Figure 11-6 Typical preamp out connections ........................................... 11-9

Figure 11-7 Electrometer input circuitry (external feedback mode) ...... 11-12

Figure 11-8 Shielded fixture construction .............................................. 11-14

Figure 11-9 “Transdiode” logarithmic current configuration ................ 11-15

Figure 11-10 Non-decade current gains ................................................... 11-16

12 Remote Operation

Figure 12-1 IEEE-488 connector ............................................................. 12-5

Figure 12-2 IEEE-488 connections ......................................................... 12-6

Figure 12-3 IEEE-488 connector location ............................................... 12-7

Figure 12-4 RS-232 interface connector ............................................... 12-18

13 Status Structure

Figure 13-1 6514 status mode structure .................................................. 13-3

Figure 13-2 16-bit status register ............................................................. 13-6

Figure 13-3 Status byte and service request ............................................ 13-7

Figure 13-4 Standard event status .......................................................... 13-12

Figure 13-5 Operation event status ........................................................ 13-13

Figure 13-6 Measurement event status .................................................. 13-14

Figure 13-7 Questionable event status ................................................... 13-15

16 DISPlay , FORMat, and SYSTem

Figure 16-1 ASCII data format ................................................................ 16-5

Figure 16-2 IEEE-754 single precision data format (32 data bits) .......... 16-5

Figure 16-3 Key-press codes ................................................................. 16-10

18 Performance V erification

Figure 18-1 Connections for volts verification ...................................... 18-10

Figure 18-2 Connections for 20µA-20mA range verification ............... 18-12

Figure 18-3 Connections for 20pA-20µA range verification ................ 18-13

Ω

Figure 18-4 Connections for ohms verification (2k
Figure 18-5 Connections for ohms verification

Ω

(200M

Figure 18-6 Connections for coulombs verification .............................. 18-18

-200GΩ ranges) .............................................. 18-17

-20MΩ ranges) ... 18-15

19 Calibration

Figure 19-1 Connections for volts calibration ......................................... 19-8

Figure 19-2 Connections for 20µA-20mA range calibration ................ 19-10

Figure 19-3 Connections for 20pA-2mA range calibration ................... 19-11

Figure 19-4 Connections for coulombs calibration ............................... 19-14

Figure 19-5 Connections for ohms calibration

Ω

and 2MΩ ranges) ................................................ 19-16

(2k

Figure 19-6 Connections for ohms calibration (2GΩ range) ................ 19-17

20 Routine Maintenance

Figure 20-1 Power module ...................................................................... 20-3

C General Measurement Considerations

Figure C-1 Power line ground loops ........................................................ C-2

Figure C-2 Eliminating ground loops ...................................................... C-3

F IEEE-488 Bus Overview

Figure F-1 IEEE-488 bus configuration .................................................. F-4

Figure F-2 IEEE-488 handshake sequence ............................................. F-6

Figure F-3 Command codes .................................................................... F-8

H Calibration Options

Figure H-1 Data transfer connections ...................................................... H-2

List of T ables

1 Getting Started

Table 1-1 SCPI commands - line frequency ........................................ 1-10

Table 1-2 Default settings .................................................................... 1-13

2 Measurement Concepts

Table 2-1 Basic measurement capabilities ............................................. 2-2

Table 2-2 SCPI commands — autozero ................................................. 2-3

Table 2-3 Display messages for zero check and zero correct .............. 2-13

Table 2-4 SCPI commands — zero check and zero correct ................. 2-15

Table 2-5 SCPI commands — input bias current and offset

Table 2-6 Summary of measurement considerations ........................... 2-19

3Volts and Ohms Measurements

Table 3-1 SCPI commands — volts and ohms function ........................ 3-7

4 Amps Measurements

Table 4-1 SCPI commands — amps function ........................................ 4-8

Table 4-2 Minimum recommended source resistance values .............. 4-11

5 Coulombs Measurements

Table 5-1 SCPI commands — coulombs function ................................. 5-5

voltage calibration .......................................................... 2-18

6 Range, Units, Digits, Rate, and Filters

Table 6-1 Measurement ranges .............................................................. 6-2

Table 6-2 SCPI commands — range and digits ..................................... 6-4

Table 6-3 SCPI commands — rate ......................................................... 6-7

Table 6-4 SCPI commands — filters ................................................... 6-10

7 Relative, mX+b and Percent (%)

Table 7-1 Range symbols for rel values ................................................. 7-3

Table 7-2 SCPI commands — relative (null) ......................................... 7-3

Table 7-3 SCPI commands — mX+b and percent ................................. 7-6

8 Buffer

Table 8-1 SCPI commands — buffer ..................................................... 8-4

9Triggering

Table 9-1 Auto delay settings ................................................................. 9-6

Table 9-2 SCPI commands — triggering ............................................... 9-9

10 Limit T ests

Table 10-1 Test limit display messages .................................................. 10-3

Table 10-2 SCPI commands — limit tests ........................................... 10-12

11 Digital I/O, Analog Outputs, and External Feedback

Table 11-1 SCPI commands — digital outputs ...................................... 11-6

Table 11-2 Example 2V analog output values ........................................ 11-7

Table 11-3 Full-range preamp out values ............................................. 11-10

Table 11-4 SCPI commands — external feedback ............................... 11-17

12 Remote Operation

Table 12-1 General bus commands ........................................................ 12-8

Table 12-2 PC serial port pinout ........................................................... 12-19

Table 12-3 RS-232 connector pinout .................................................... 12-19

13 Status Structure

Table 13-1 Common and SCPI commands — reset registers and

clear queues .................................................................... 13-4

Table 13-2 SCPI command — data formats for reading

status registers ................................................................ 13-6

Table 13-3 Common commands — status byte and service request

enable registers ............................................................... 13-9

Table 13-4 Common and SCPI commands — condition registers ....... 13-16

Table 13-5 Common and SCPI commands — event registers ............. 13-16

Table 13-6 Common and SCPI commands — event enable

registers ......................................................................... 13-17

Table 13-7 SCPI commands — error queue ......................................... 13-20

14 Common Commands

Table 14-1 IEEE-488.2 common commands and queries ...................... 14-2

15 SCPI Signal Oriented Measurement Commands

Table 15-1 Signal oriented measurement command summary .............. 15-2

16 DISPlay , FORMat, and SYSTem

Table 16-1 SCPI commands — display ................................................. 16-2

Table 16-2 SCPI commands — data format ........................................... 16-4

Table 16-3 SCPI commands — system .................................................. 16-8

17 SCPI Reference T ables

Table 17-1 CALCulate command summary .......................................... 17-2

Table 17-2 FORMat command summary ............................................... 17-5

Table 17-3 DISPlay command summary ............................................... 17-5

Table 17-4 SENSe command summary ................................................. 17-6

Table 17-5 STATus command summary ................................................ 17-9

Table 17-6 SOURce command summary ............................................... 17-9

Table 17-7 SYSTem command summary ............................................ 17-11

Table 17-8 TRACe command summary .............................................. 17-12

Table 17-9 TRIGger command summary ............................................ 17-13

18 Performance V erification

Table 18-1 Recommended verification equipment ................................ 18-4

Table 18-2 Voltage measurement accuracy reading limits ................... 18-11

Table 18-3 20mA-20mA range current measurement accuracy

reading limits ................................................................ 18-13

Table 18-4 20pA-2µA range current measurement accuracy

reading limits ................................................................ 18-14

Ω

Table 18-5 2k

Table 18-6 200M

Table 18-7 Coulombs measurement accuracy reading limits .............. 18-19

-20MΩ range resistance measurement

accuracy limits ............................................................. 18-16

Ω

-200GΩ resistance measurement

accuracy limits ............................................................. 18-17

19 Calibration

Table 19-1 Recommended calibration equipment ................................. 19-4

Table 19-2 Calibration menu ................................................................. 19-5

Table 19-3 Volts calibration summary ................................................... 19-9

Table 19-4 20mA-20mA range amps calibration summary ................. 19-11

Table 19-5 20pA-2µA range amps calibration summary ..................... 19-13

Table 19-6 Coulombs calibration summary ......................................... 19-15

Table 19-7 Ohms calibration summary ................................................ 19-17

20 Routine Maintenance

Table 20-1 Power line fuse ..................................................................... 20-3

Table 20-2 Front panel tests ................................................................... 20-4

B Status and Error Messages

Table B-1 Status and error messages ..................................................... B-2

D DDC Emulation Commands

Table D-1 Device dependent command summary ................................. D-2

F IEEE-488 Bus Overview

Table F-1 IEEE-488 bus command summary ........................................ F-7

Table F-2 Hexadecimal and decimal command codes ........................ F-10

Table F-3 Typical bus sequence ........................................................... F-11

Table F-4 Typical addressed command sequence ................................ F-11

Table F-5 IEEE command groups ....................................................... F-12

Table F-6 Model 6514 interface function codes .................................. F-13

G IEEE-488 and SCPI Conformance Information

Table G-1 IEEE-488 documentation requirements ................................ G-2

Table G-2 Coupled commands ............................................................... G-4

H Calibration Options

Table H-1 Calibration commands .......................................................... H-4

Getting Started

•

General information

tion, contact information, safety symbols and terms, inspection, and available options
and accessories.

•

System electrometer features

•

Front and rear panel familiarization

instrument.

•

Power-up

power line frequency, and the power-up sequence.

•

Display

•

Default settings — Covers the five instrument setup configurations a vailable to the user;

three user defined, GPIB defaults, or factory defaults.

•

SCPI programming

— Covers line power connection, line voltage setting, fuse replacement,

— Provides information about the display of Model 6514.

— Covers general information that includes warranty informa-

— Summarizes the features of Model 6514.

— Summarizes the controls and connectors of the

— Explains how SCPI commands are presented in this manual.

1

1-2 Getting Started

General information

Warranty information

Warranty information is located at the front of this manual. Should your Model 6514 require
warranty service, contact the Keithley representati ve or authorized repair f acility in your area for
further information. When returning the instrument for repair, be sure to fill out and include the
service form at the back of this manual to provide the repair facility with the necessary
information.

Contact information

Worldwide phone numbers are listed at the front of this manual. If you have any questions,
please contact your local Keithley representative or call one of our Application Engineers at
1-800-348-3735 (U.S. and Canada only).

Safety symbols and terms

The following symbols and terms may be found on the instrument or used in this manual:

!

The symbol on an instrument indicates that the user should refer to the operating instruc­tions located in the manual.

The symbol on the instrument shows that high voltage may be present on the termi­nal(s). Use standard safety precautions to avoid personal contact with these voltages.

WARNING

The
injury or death. Always read the associated information very carefully before performing the
indicated procedure.

The

CAUTION

ment. Such damage may invalidate the warranty.

heading used in this manual explains dangers that might result in personal

heading used in this manual explains hazards that could damage the instru-

Inspection

Model 6514 was carefully inspected electrically and mechanically before shipment. After
unpacking all items from the shipping carton, check for any obvious signs of physical damage
that may have occurred during transit. (There may be a protective film over the display lens,
which can be removed). Report any damage to the shipping agent immediately. Save the original
packing carton for possible future shipment. The following items are included with e very Model
6514 order:

• Model 6514 System Electrometer with line cord.

• Model 237-ALG-2 triax cable.

• Accessories as ordered.

• Certificate of calibration.

• Model 6514 Instruction Manual (P/N 6514-901-01).

• Manual Addenda (pertains to any improvements or changes concerning the instrument

If an additional manual is required, order the appropriate manual package. The manual pack­ages include a manual and any pertinent addenda.

or manual).

Options and accessories

Input cables, connectors and adapters

Model 237-ALG-2 — This is a 6.6 ft (2-meter) low-noise triax cable terminated with a 3- slot

male triax connector on one end and 3 alligator clips on the other. (One Model 237-ALG-2 is
included).

Model 237-BNC-TRX adapter — This is a male BNC to 3-lug female triax connector

(guard disconnected). It is used to terminate a triax cable with a BNC plug.

Model 237-TRX-T adapter — This is a 3-slot male to dual 3-lug female triax tee adapter for

use with 7078-TRX triax cables.

Model 237-TRX-TBC connector — This is a 3-lug female triax b ulkhead (internal mount)

connector with cap for assembly of custom test fixtures and interface connections.

Model 7078-TRX-TBC connector — This is a 3-lug female triax bulkhead (external mount)

connector with cap for assembly of custom test fixtures and interface connections.

Model 7078-TRX-3, 7078-TRX-10 and Models 7078-TRX-20 triax cables — These are

low noise triax cables terminated at both ends with 3-slot male triax connectors. The -3 model
is 3 ft (0.9m) in length, the -10 model is 10 ft (3m) in length, and the -20 model is 20 ft (6m) in
length.

Getting Started 1-3

CS-751 barrel adapter — This is a barrel adapter that allows you to connect tw o triax cables

together. Both ends of the adapter are terminated with 3-lug female triax connectors.

GPIB and trigger link cables and adapters

Models 7007-1 and 7007-2 shielded GPIB cables — Connect Model 6514 to the GPIB b us

using shielded cables and connectors to reduce electromagnetic interference (EMI). Model
7007-1 is lm long; Model 7007-2 is 2m long.

Models 8501-1 and 8501-2 trigger link cables — Connect Model 6514 to other instruments

with Trigger Link connectors (e.g., Model 7001 Switch System). Model 8501-1 is lm long;
Model 8501-2 is 2m long.

Model 8502 trigger link adapter — Lets you connect any of the six trigger link lines of

Model 6514 to instruments that use the standard BNC trigger connectors.

Model 8503 DIN to BNC trigger cable — Lets you connect trigger link lines one (Voltmeter

Complete) and two (External Trigger) of Model 6514 to instruments that use BNC trigger con­nectors. Model 8503 is lm long.

1-4 Getting Started

Rack mount kits

Model 4288-1 single fixed rack mount kit — Mounts a single Model 6514 in a standard
19-inch rack.

Model 4288-2 side-by-side rack mount kit — Mounts two instruments (Models 182, 428,
486, 487, 2000, 2001, 2002, 2010, 2400, 2410, 2420, 2430, 6430, 6514, 6517 A, 7001)
side-by-side in a standard 19-inch rack.

Model 4288-4 side-by-side rack mount kit — Mounts Model 6514 and a 5.25-inch instru­ment (Models 195A, 196, 220, 224, 230, 263, 595, 614, 617, 705, 740, 775A, 6512) side-by-side
in a standard 19-inch rack.

Carrying case

Model 1050 padded carrying case — A carrying case for Model 6514. Includes handles and
shoulder strap.

System electrometer features

Model 6514 is a 6½-digit high-performance system electrometer . It can measure voltage, cur ­rent, resistance and charge. Details on its measurement capabilities are explained in Section 2 of
this manual (see “Measurement Overview”).

Features of Model 6514 System Electrometer include:

• Setup storage — Five instrument setups (three user , GPIB defaults and f actory defaults)

can be saved and recalled.

• mX+b and percent — These calculations provide mathematical manipulation of

readings.

• Relative — Null offsets or establish baseline values.

• Buffer — Store up to 2500 readings in the internal buffer.

• Limits — Set up to two stages of high and low reading limits to test devices.

• Digital I/O port — Four output lines and one input line to control external circuitry. Use

as an interface between limit tests and component handler.

• Analog outputs — Provides a 2V analog output for a full range input. Preamp out pro-

vides a driven guard for Volts, or can be used for external feedback measurements.

• External feedback — Extends the measurement capabilities of the electrometer; loga-

rithmic currents, non-decade current ranges and non-standard charge ranges.

• Remote interface — Model 6514 can be controlled using the IEEE-488 interface

(GPIB) or the RS-232 interface.

• GPIB programming language — When using the GPIB, the instrument can be pro-

grammed using the SCPI or DDC programming language.

Front and rear panel familiarization

Front panel summary

The front panel of Model 6514 is shown in Figure 1-1.

Figure 1-1

Model
6514
front panel

4

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

TALK
LSTN
SRQ
SHIFT

TIMER

HOLD TRIG FAST MED SLOW AUTO ERR

REL FILT

BUFFER

Getting Started 1-5

MATH
REAR

4W

STAT

V-DROP

AUTO-DIS

CONF-LIM

Q

GPIB

XFBK ZCHK

UNITS

CONF-ARM

SHIFT

1

LOCAL

POWER

V

MX+B

AVG

TEST CAL

STORE

MEDN

RCLL

%

I

Ω

VAL

REL LIMIT

SAVE SETUP

DELAY DAMP

23

6514 SYSTEM ELECTROMETER

RS-232

ZCOR

GRD

NPLC

RATEDIGIT

CONF-TRIG

EXIT ENTERHALT TRIG

RANGE

AUTO

RANGE

5

NOTE Most keys provide a dual function or oper ation. The nomenclature on a ke y indicates

its unshifted function/operation, which is selected by pr essing the k ey. Nomenclatur e
(in blue) above a key indicates its shifted function. A shifted function is selected by
pressing the SHIFT key and then the function/operation key.

1 Special keys and power switch

SHIFT Use to select a shifted function or operation.
LOCAL Cancels GPIB remote mode.
POWER Power switch. In position turns 6514 on (I), out position turns it off (O).

2 Function and operation keys

Top Row

Unshifted
V Selects voltage measurement function.
I Selects current measurement function.
Ω Selects resistance measurement function.
Q Selects charge measurement function.
XFBK Enables/disables External Feedback.
ZCHK Enables/disables Zero Check.
ZCOR Enables/disables Zero Correct.
GRD Enables/disables Guard.

1-6 Getting Started

Shifted
V-DROP Enables/disables V-drop measurements for Ω function.
AUTO-DIS Sets and enables/disables Auto Discharge for charge measurements.
GPIB Configures and enables/disables GPIB interface.
RS-232 Configures and enables/disables RS-232 interface.

Middle Row

Unshifted
AVG Configures and enables/disables digital filter.
MEDN Configures and enables/disables median filter.
REL Enables/disables Relative (Rel).
LIMIT Performs configured limit tests.
DIGIT Sets display resolution.
RATE Selects measurement rate.

 and  Controls cursor position for making selections or editing values.

Shifted
MX+B Configures and enables/disables mX+b math function.
% Configures and enables/disables Percent math function.
VAL Sets Rel value and enables Rel.
CONF-LIM Configures limit tests.
UNITS Selects engineering units for scientific notation for display readings.
NPLC Set rate by setting PLC value.

Bottom Row

Unshifted
STORE Sets the number of readings to store and enables the buffer.
RCLL Displays stored readings (including maximum, minimum, peak-to-peak, average,

and standard deviation). The  and  range keys scroll through the buffer, and the 

or  key toggles between reading number and reading.
DELAY Sets user delay between trigger and measurement.
DAMP Enables/disables damping for current measurements.
HALT Stops measurement process. Puts 6514 in idle state.
TRIG Trigger measurement(s). Takes 6514 out of idle state.
EXIT Cancels selection, moves back to measurement display.
ENTER Accepts selection, moves to next choice or back to measurement display.

Shifted
TEST Performs key-press test or display test.
CAL Accesses calibration.
SAVE Saves present setup to a memory location.
SETUP Restores setup stored in a memory location, or to GPIB or factory defaults.
CONF-ARM Configures Arm Layer of trigger model.
CONF-TRIG Configures Trigger Layer of trigger model.

3 Range keys

 Selects the next higher voltage measurement range.
 Selects the next lower voltage measurement range.

AUTO Enables/disables autorange.

4 Display annunciators

* (asterisk) Readings being stored in buffer.
↔ (more) Indicates additional selections are available.
AUTO Autorange enabled.
BUFFER Recalling readings stored in buffer.
ERR Questionable reading, or invalid cal step.
FAST Fast (0.1 PLC) reading rate selected.
FILT Filter enabled.
LSTN Instrument addressed to listen over GPIB.
MATH mX+b or Percent (%) calculation enabled.
MED Medium (1 PLC) reading rate selected.
REL Relative enabled for present measurement function.
REM Instrument in GPIB remote mode.
SHIFT Accessing a shifted key.
SLOW Slow reading rate selected; 6 PLC for 60Hz or 5 PLC for 50Hz.
SRQ Service request over GPIB.
STAT Displaying buffer statistics.
TALK Instrument addressed to talk over GPIB bus.
TIMER Timer controlled triggering in use.
TRIG External triggering (GPIB or trigger link) selected.

5 Handle

Pull out and rotate to desired position.

Getting Started 1-7

1-8 Getting Started

Rear panel summary

The rear panel of Model 6514 is shown in Figure 1-2.

Figure 1-2

Model 6514
rear panel

1

INPUT 250V PK

INPUT PREAMP

OFF

ON

V, GUARD

(PROGRAMMABLE)

PREAMP OUT

250V PK

GUARD

(FOLLOWS

INPUT)

2

(INTERNAL)

2V ANALOG

10K

3

OUTPUT

PREAMP
2V ANALOG

COM

!

COMMON CHASSIS

TRIGGER LINK

OUT
OUTPUT

4

LINE RATING

!

FUSE LINE

630mA

(SB)

315mAT

(SB)

50, 60Hz

60 VA MAX

T

100 VAC
120 VAC

220 VAC
240 VAC

5

RS232DIGITAL I/O

120

6

MADE IN

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

U.S.A.

789 10

1 INPUT

This standard 3-lug female triax connector is used to connect the signal to be measured to the input
of Model 6514. Mates to a triax cable terminated with a 3-lug male triax connector.

2 PREAMP OUT

Provides a guard output for Volts measurements. Can be used as an inverting output or with external
feedback for the Amps and Coulombs modes.

32V ANALOG OUTPUT

Provides a scaled DC output voltage. A full range input will result in a 2V analog output.
For the volts function, the output is non-inverting.

4 COMMON

Use as input low, or the common for the 2V Analog Output and Preamp Out.

5 CHASSIS

This terminal is connected to the chassis of Model 6514 and to power line earth ground via the power
line cord. For floating measurements (up to 500V peak), remove the ground link between COMMON
and CHASSIS.